The background description provided herein is for the purpose of generally presenting the context of the disclosure and may not constitute prior art.
A linear actuator generally includes a motor that provides torque to rotate a lead screw, which in turn translates the rotary motion into a linear motion. The linear actuator typically includes a complicated coupling device including multiple components to connect the motor shaft to the lead screw. The multiple components need to have small manufacturing and assembly tolerance to ensure proper alignment between the motor shaft and the lead screw, thereby increasing manufacturing costs. The manufacturing costs are higher when the linear actuators are designed for nano-scale positioning.
Further, the coupling device typically extends a significant length to provide room for the linear movement of the lead screw. As such, the complicated coupling system undesirably increases the space required for the linear actuator and further reduces the stiffness of the linear actuator. Clearances among the multiple components of the coupling device also result in reduced stiffness of the linear actuators.